Overnight full closures of southbound I-25 near Larkspur needed for bridge reconstruction in March and April

Travel Advisory

March 10, 2020 - Denver Metro Area - Receive updates about closures by texting I25Gap to 21000 and following the I-25 South Gap Facebook Page

LARKSPUR — As part of the Interstate 25 South Gap project to improve safety and travel reliability, crews are rebuilding the Spruce Mountain Road bridge near Larkspur. Starting in March, the work will require a series of overnight closures of southbound I-25, with motorists using a five-minute detour route.

The reconstruction of the Spruce Mountain Road bridge requires a series of overnight closures of southbound I-25 from 7 p.m. to 5 a.m.  Work includes setting bridge beams and deck panels.

Nightly closures are scheduled to begin on Thursday, March 12 and last through Monday, March 23. These dates are likely to change due to weather and progress made each night. Please sign up for text alerts (text I25GAP to 21000) and follow our Facebook page (@I25SouthGapProject) for most current construction closure dates.

The new bridge construction will allow for wider lanes and safer travel entering and exiting Larkspur using the Spruce Mountain Road flyover.  Construction of the bridge is expected to finish later this year. The Spruce Mountain Road bridge is one of three bridges under construction in the one-mile span between Upper Lake Gulch Road and Spruce Mountain Road. In all, the I-25 South Gap project includes five bridge replacements and four new wildlife underpasses.

Southbound and Northbound I-25 Detour Details (see detour map at end of release)*

Southbound I-25 Detour - Southbound I-25 traffic will funnel into one lane just north of Spruce Mountain Road, where all traffic will exit. Motorists will then take Spruce Mountain Road south to the Upper Lake Gulch Road on-ramp to continue on southbound I-25. This detour is expected to take an average of five minutes.

Northbound I-25 Single-Lane Closure - Northbound I-25 traffic will funnel into one lane on the existing I-25 lanes and travel through the closure limits from the Upper Lake Gulch Road exit through the Spruce Mountain Road exit. Expect slower speeds.

Crews will begin setting up traffic control signs at 6 p.m., which may cause minor traffic impacts each night before the actual closure begins at 7 p.m. Please expect delays. Crews appreciate your patience.

 Additional Southbound I-25 Closures

In April 2020, crews will require another overnight closure of southbound I-25 to pour the Spruce Mountain Road bridge deck over I-25.

Additional Impacts Near Larkspur

  • A nine-month closure of the Spruce Mountain Road on-ramp to northbound I-25 began in October 2019 for bridge demolition and reconstruction. Alternate access to I-25 is via Upper Lake Gulch Road.

  • A nine-month closure of the southbound I-25 off-ramp to Upper Lake Gulch Road also began in October 2019. This ramp must remain closed as crews shift traffic to the far west for bridge work in this area.

  • Various closures of the southbound I-25 off-ramp to Spruce Mountain Road are also required. When this ramp is closed, crews will open the southbound I-25 off-ramp to Upper Lake Gulch Road into a temporary configuration.

  • Detour routes for each of the previous impacts will be heavily signed. For more information on each impact, follow the I-25 South Gap Facebook page (@I25SouthGapProject) or visit the I-25 South Gap website at i25gap.codot.gov.

Two lanes will remain open in each direction of I-25 during the daytime peak travel periods. All construction schedules are weather-dependent.

About the I-25 South Gap project

CDOT is improving 18 miles of I-25 between Monument and Castle Rock by widening the highway from two to three lanes in each direction. The new lane will operate as an Express Lane, allowing motorists the choice of taking the Express Lane for a faster, more reliable travel time in exchange for a toll. Express Lanes will be free to vehicles with three or more people and motorcycles. All travelers will have the choice of taking the general-purpose lanes for free.

 The $350 million project also includes shoulder widening, rebuilding bridges, new wildlife crossings, resurfacing with new pavement and modernizing technology. Project completion will occur in 2022.

Travel options to improve commutes are available during construction. Some of the services include a new Bustang route from Colorado Springs to the Denver Tech Center. CDOT is partnering with the Denver Regional Council of Governments' Way to Go program to provide more commuting options, such as incentives to vanpool and carpool. 

Southbound I-25 closure detour map at Upper Lake Gulch Road

 Stay Informed

  • Project website for weekly updates: i25gap.codot.gov
  • Construction hotline: 720-745-5434
  • Email updates: [email protected]
  • Text alerts: text I25GAP to 21000
  • Facebook updates: Facebook.com/I25SouthGapProject
  • Twitter updates: @coloradodot


The following tips are to help you stay safe while traveling through maintenance and construction work zones.

    Do not speed in work zones. Obey the posted speed limits.

    Stay Alert! Expect the unexpected.

    Watch for workers. Drive with caution.

    Don't change lanes unnecessarily.

    Avoid using mobile devices such as phones while driving in work zones.

    Turn on headlights so that workers and other drivers can see you.

    Be especially alert at night while driving in work zones.

    Expect delays, especially during peak travel times.

     Allow ample space between you and the car in front of you.

    Anticipate lane shifts and merge when directed to do so.

    Be patient!


In early 2019, CDOT announced its Whole System. Whole Safety initiative to heighten safety awareness. This initiative takes a systematic, statewide approach to safety combining the benefits of CDOT’s programs that address driving behaviors, our built environment and the organization's operations. The goal is to improve the safety of Colorado’s transportation network by reducing the rate and severity of crashes and improving the safety of all transportation modes. The program has one simple mission – to get everyone home safely.

*Detour Map